1. Field of the Invention
The invention belongs to the field of the further processing of printed products and relates, in particular, to an apparatus for, and a method of, inserting flat articles into a folded printed product. Examples of such flat articles are printed products, printed sub-products or additional products, newspaper sections, trade samples, leaflets, flyers and other inserts.
2. Description of Related Art
For the purpose of inserting flat articles between the two product parts of a folded printed product, it is known for the printed products coming from the rotary printing machine to be transferred to a separate apparatus, to be retained and opened therein and for the flat articles to be introduced and for the resulting end product to be removed and conveyed further.
EP-B 0 448 679 discloses a method and an apparatus which are intended for inserting flat articles into a folded printed product and in which the printed products, retained by grippers of a gripper conveyor, are moved to a feed station for the flat articles. In the region of the feed station, the grippers are opened briefly, the flat articles are introduced into the previously opened products, and the grippers are then closed again. They then convey the product, including the article, further without the product having been removed from the gripper. In the open state of the gripper, there is the problem of the products being able to fall out of the gripper. For the purpose of supporting the products, a pocket conveyor is thus provided, and the pockets of this pocket conveyor are moved synchronously to the grippers, in the region upstream and downstream of the feed station, along a path which is parallel to the movement path of the grippers. If the gripper is open, the outer surfaces of the two product parts butt against the respective side surfaces of the pockets. One of the product parts is fixed on the side surface by a clamping element, and therefore the product is held open. The folding edge is supported at all times by a channel-like extension, which is fixed to one of the jaws of the gripper. This means that, in the open state of the gripper, lateral tilting of the product is also prevented. Once the flat article has been introduced and the gripper has been closed, the movement paths of the grippers and of the pockets separate again.
One disadvantage of the known apparatus is that it is not possible to use conventional grippers, and thus known gripper conveyors cannot be used without design adaptations. This is because, in the case of conventional grippers, opening of the gripper would result in the product sliding deeper into the then open gripper mouth and also shifting transversely to the gripper-movement direction. The pockets disclosed in EP-B 0 448 679 have just two lateral supporting walls, but no pocket base, and this configuration makes it unsuitable for supporting the product on the folding edge. The channel makes the grippers of EP-B 0 448 679 much wider than the normal grippers, and this may be disadvantageous, for space-related reasons, for processes taking place upstream or downstream.
A further problem which is not solved by the known apparatus is the adaptation to different product formats. Since the clamping elements are located at the outer ends of the pocket walls, it is only products with a certain length adapted to the pocket size which can be retained.
Finally, the known apparatus has the problem of the grippers having to have a certain minimum spacing in order that the pockets, with their angled apart pocket walls, can be moved inbetween the grippers and the products retained thereby. This means that it is not possible for the products to be conveyed in a close-packed formation in which, for example, the product spacings in the conveying direction are smaller than the product lengths. However, it is precisely this scenario which is typical in the case of known gripper conveyors, and it is for this reason as well that these cannot be used.
Furthermore, EP-B 1 809 557 discloses an apparatus which is intended for inserting flat articles into printed products and in which the printed products likewise remain in the gripper during insertion of the articles. The grippers run around a deflection. In the lower region of the deflection, the folded products are opened in a hanging state by an opening means, wherein the free ends of the products are moved apart from one another. The product edges of respectively adjacent products are jointly clamped together by clamping elements which are moved along at a constant spacing by the grippers in the region of the deflection, and therefore the product is held open even with a change in its orientation. The articles are introduced when the open product is oriented upward; in this state, the gripper is also opened and then closed again in order to retain the product together with the inserted article. The invention has the advantage that the product is well positioned by virtue of the free product edges being clamped firmly. However, the adaptation to different formats involves high outlay, and products with a short length in the axial direction, on account of the constant spacing between the grippers and the clamping elements, have a large opening angle, which can adversely affect sensitive products.